Lawn mower runs really poorly

[LarsMunk]

Hello,
I'm new here, so sorry if I am using this forum wrong.

I have a Stiga lawn mower thst has a B&S engine.

When I start it, it runs really low rpm, runs uneven and then dies and sometimes it wont start.

I Have recorded how it runs here:

I have cleaned the carb and have tried that a lot of times with other lawn mower with great succes, but i havnt tried this issue before.

It is a ohv and I suspect the valves might be incorrectly adjusted?

 

[Rivets]

Check the choke, I don’t think it is opening slightly on start up. If you need more help, post all engine numbers and a couple of close up pics of the carb and linkage.

 

[LarsMunk]

The choke is controlled from the gas lever, so I have to manually adjust it, so it ins't auto choke.

I have some pictures from the linkage and its a GGP engine instead of a BS. Engine name is GGP WBE0702.

I have found out, that sometimes it starts and runs fine, this is typically after an hour where I haven't tried to start it. But then it dies and then I have the same problems again.
I have a video of that here:

As you can see in the video, when it is about to die I can "catch" it with the choke?

I have a picture of the linkage here:

https://imgur.com/SvIzhvE

 

[Rivets]

If you can catch it with the choke I’m guessing you have a lean running condition. There #hould b3 a black jet under the idle speed screw. Remove the screw and pry up on the jet to remove it. Check to see that the hole on the bottom is clear.

 

[LarsMunk]

I have cleaned the black jet, but it's still the same.

Could it be a damaged flywheel key?

Or the valves that is set incorrectly?

 

[mistermowerman]

I have cleaned the black jet, but it's still the same.

Could it be a damaged flywheel key?

Or the valves that is set incorrectly?

Hello, have you dropped your float chamber off and checked to see if your main jet is not blocked, you will find the main jet either as part of the bolt that holds the float bowl up or in the centre tube (the part the bolt goes into that holds the bowl up)if the jet is in the centre tube it will need to come out but be careful as it is made of brass with a screw slot in it . I suggest that you use a good sharp screw driver and with it in your hand make sure all the holes are clear.

 

[LarsMunk]

Hello, yes I have cleaned the main jet too and the whole carburator, but it doesnt help unfutunately.

Normally cleaning the carb works, but not this time.

 

[bertsmobile1]

My go to is the can of carb cleaner.
If I can keep the engine running by sending short shots of carb cleaner down the carb throat then I have a fuel supply problem.
Some carbs have taken hours of cooking in the ultra sound before they came good

 

[mistermowerman]

My go to is the can of carb cleaner.
If I can keep the engine running by sending short shots of carb cleaner down the carb throat then I have a fuel supply problem.
Some carbs have taken hours of cooking in the ultra sound before they came good

Hello, yes I have cleaned the main jet too and the whole carburator, but it doesnt help unfutunately.

Normally cleaning the carb works, but not this time.

Hello, i think long term you may have to get a new carb, the engine you have got i believe is a stiga engine not a briggs, the parts for these engines are a lot cheaper than you would think so may be using the numbers on the engine see if there is another carb out there at the right price.

 

[LarsMunk]

I finally figured it out. It was the spark plug. I must have been using a spark plug with the wrong specs or something like that.

After watching some youtube videos with Honda engines that acted the same way where the fix was a new spark plug, and I decided to give that a try. So i went through some different spark plugs and then I found one that worked.